1. Field of the Invention
The present invention relates to a picker of picking up a device for transport in a handler, and more particularly, to a device picker in a handler for picking up a plurality of pairs of devices simultaneously at one side of the handler to transfer to load them to the other side.
2. Discussion of the Related Art
Generally, devices such as memory semiconductor devices, n-memory semiconductor devices, and the like and modules having such devices arranged on a single substrate to construct circuits are inspected by various tests for shipment. The handler is an apparatus used for testing the devices and module RAMs automatically.
Most of the handlers carries out not only general performance test at room temperature but also high and low temperature tests for checking whether the devices and module RAMs operate normally by building up environments of extremely high or low temperature through an electric heater or liquefied nitrogen jetting system in an airtight chamber.
FIG. 1 illustrates a diagram of a handler for testing devices such as memory semiconductor packages.
Referring to FIG. 1, a loading stacker 10, on which user trays receiving a plurality of devices to be tested are loaded, is installed in a front part of the handler. And, an unloading stacker 20 is installed at one side of the loading stacker 10 so that the devices are classified by test results after completion of the tests to be received in the user trays.
Buffer units 40, on which the devices transferred from the loading stacker 10 are temporarily loaded, are installed to move back and forth at both sides of a middle part of the handler.
And, an exchange unit 50 is installed between the buffer units 40. In the exchange unit 50, carried out are a process of transferring devices of the buffer unit 40 to be tested and reloading the transferred devices on a test trays T and another process of loading the test-completed devices of the test trays on the buffer units 40.
Between the handler front part on which the loading and unloading stackers 10 and 20 are arranged and the handler middle part on which the exchange and buffer units 50 and 40 are arranged, first and second pickers 31 and 32 moving linearly along an X-Y axis to pick up to transport the devices are installed. The first picker 31 moves between the loading and unloading stackers 10 and 20 and the buffer units 4 to pick up to transport the devices, and the second picker 32 moves between the buffer units and exchange unit 50 to pick up to transport the devices.
In a rear part of the handler, installed is a test site 70 for testing the performance of the devices at a predetermined temperature by conveying the test trays T having the devices loaded thereon sequentially after high or low temperature test environments have been built in a plurality of separate airtight chambers.
However, the first and second pickers 31 and 32 of the above-constituted handler are designed to pick up to transport a pair of devices only each time, thereby reducing test efficiency.
If the number of the pickup means of each picker is increased, the overall constitution of the pickers becomes complicated to have difficulty in controlling malfunction and maintenance of the apparatus.